LTV:CAC Ratio

What is LTV:CAC? LTV:CAC is the ratio of customer lifetime value to acquisition cost — the single most-cited metric for whether a business can scale profitably. LTV (Lifetime Value) represents the total gross margin a customer generates over their entire relationship with your brand. CAC (Customer Acquisition Cost) is what you spend to acquire them. The ratio between these two numbers determines whether you have a sustainable growth engine or a leaky bucket. Investors, CFOs, and growth leaders use it to answer one question: can this business scale profitably?

A ratio of 3:1 is the standard benchmark — it means every acquisition dollar returns three dollars in lifetime margin, leaving room for overhead, fixed costs, and profit. Below 3:1, your margins are too thin for comfortable scaling. Below 1:1, you are literally paying more to acquire customers than they will ever be worth.

The payback period is equally important. Even a 5:1 ratio is problematic if payback takes 18 months because your cash is locked up. Most healthy DTC brands aim for payback under 6 months. This calculator factors in AOV, purchase frequency, customer lifespan, and gross margin to compute a margin-adjusted LTV. If your ratio is below 3:1, the two levers are improving retention (increases LTV) and reducing acquisition costs (lowers CAC).

Even small improvements in repeat purchase rate have an outsized impact on LTV. Moving repeat purchase rate from 28% to 35% can shift your LTV:CAC from 2.5:1 to 3.5:1, transforming an unprofitable growth model into a scalable one.